Oligonucleotides containing 7- or 8-methyl-7-deazaguanine: Steric requirements of major groove substituents on the DNA structure

Abstract

Methyl groups in alternating octanucleotides containing 7-methyl-7-deazaguanine and cytosine have steric freedom and maintain the B-DNA structure, whereas the isomeric 8-methyl-7-deazaguanine causes a B-Z transition.